13b four port build ideas. 12a GSLSE vs 13BT
 

This is for a natural aspiration, fuel injection project.

Basically, i have two great condition GSLSE rotor housings, some 12a irons and the like. That combo would give me a 13b four port. NOW, the other option i have is to get a 13BT engine, and used the housings and irons from that for the base.

While i have the GSLSE 12a parts, would it be worth it to get the turbo stuffs instead?

So basically here are the three engine options, basically in order of cost (cheap to expensive). But what do you think the maximum potential would be? I could use RE manifolds for the last option, where as i would opt for something like a sidedraft and EFI Throttle body for the 1 and 2....

Engine 1;
*GSLSE rotor housings
*12a outer irons, ported
*GSLSE center iron
*9.7:1 rotors OR rx8 rotors

Engine 2:
*13bt irons
*whatever housings i can find from a s4+ 13b
*9.7:1 rotors or rx8 rotors

Engine 3:
*either RE or REW rotor housings
*either RE or REW irons
*either 9.7 or rx8 rotors.

I would not use RX-8 rotors. S5 is the best if you can find them.

As far as 12A vs. TII end plates, I don't believe there's all that much difference in terms of how much porting you can do. What are you planning for the intake manifold and throttle body? If you want to use a TII/RE(W) setup, use TII/RE(W) irons. The reason for this is because the port runners of S4 and later turbo engines go in at sort of an angle so the intake manifold can clear the turbo. REW (possibly also RE?) front plates are better because of the bigger oil pump. Also, the chrome on S4+ rotor housings is better than that of GSL-SE rotor housings, if I'm not mistaken.

If you're going with a custom manifold and throttle body, use 12A end plates and a 12A intermediate plate and mount the primary injectors somewhere else. The reason for this is because the 12A intermediate plate has a LOT more room for porting than the later intermediate plates.

but for the quaility of control, we had a harder time get things perfect with the injectors up stream. Manifold wise i plan on using a side draft (lakewood style) manifold.

Fair enough. In that case, I'd probably just use the 12A end plates since you already have them.

Really? Have you used RX8 rotors? S5 N/A rotors are getting very hard find with the resulting expense increase. All for an inferior rotor.

See http://www.rotarycarclub.com/showthread.php?t=4658
And my own website (below) for info on using RX8 rotors and their benefits.

i am probably going to opt for the Rx8 rotors just to see for myself. hear say is not my style.